1. Field of the Invention
The present invention relates to a novel group of compounds having antibiotic, antifungal and/or cytostatic properties, which are obtainable from myxobacteria, especially of the genus Sorangium, preferably Sorangium cellulosum. One representative of this group of compounds is currently named Disorazole Z and Disorazole Z-epoxide, respectively, with specific substituents and a specific configuration of unsaturated bonds with its cyclic core structure.
2. Description of Related Art
It is known that myxobacteria produce a large variety of biologically active compounds, which are also termed secondary metabolites. Among these secondary metabolites, the group of Disorazoles has attracted attention as inhibitors for the polymerization of tubulin, for the induction of apoptosis and for the arrest of the cell cycle or inhibition of cell proliferation, even at low concentrations.
Although the compounds of the present invention can be isolated from producer strains of the genus Sorangium, they have a substantially differing backbone structure to known Disorazoles or Chivosazoles.
Secondary metabolites isolated from myxobacteria of the genus Sorangium, that have been termed Disorazoles can be found in Jansen et al., Liebigs Ann. Chem. 1994, 759-773. One structural formula representative of Disorazoles, termed Disorazole A1 through A7, depending on their substituents, is given below:

Disorazoles comprise a heterogenous group including two oxazoles in a macrolide ring. In general, Disorazoles have a backbone of a symmetrical circular structure, which can be subdivided into two halves, connected by ester groups, forming a macrolide ring that comprises a total of 34 atoms, part of which carry further substituent groups. Adjacent to one of the ester groups, each of these molecule halves comprises an oxazole ring and a chain of 10 or 12 carbon atoms, followed by an ester group forming the connection to the other molecule half. The chain of 10 to 12 carbon atoms shows a wide range of variations in respect of the arrangement and number of double bonds and further substituents, e.g. epoxy groups, hydroxyl groups and further substituent saturated or partially unsaturated alkyl groups.
Another group of secondary metabolites obtainable from myxobacteria, especially Sorangium cellulosum is termed Chivosazoles, the backbone structure of which is given below as identified by Jansen et al. (Liebigs Ann./Recueil 1997, 1725-1732 (1997)). In general, Chivosazoles can be described as glycosides of 6-deoxyglucopyranose derivatives of an aglycon which includes an oxazole in its 31-membered macrolide ring. The aglycon itself is termed Chivosazole F, showing antibiotic and cytotoxic activities:
Above: Chivosazole aglycon (F), wherein R1 is H or —CH3. Substituents for R2 are termed chinovosyl derivatives.